There is known a laminated iron core used as the core or stator of a motor. As the laminated iron core, there is known a laminated iron core formed by laminating annular iron core pieces and mainly used in a small motor, or a laminated iron core formed by laminating multiple divided iron core pieces which are obtained by dividing an annular iron core piece (for example, see Patent Literatures 1 and 2).
The multiple iron core pieces or divided iron core pieces used in an ordinary laminated iron core respectively include a caulking portion which mechanically connects together iron core pieces or divided iron core pieces mutually adjoining in the laminating direction. Also, the divided iron core pieces constituting the laminated iron core disclosed in Patent Literatures 1 and 2 respectively include a larger number of caulking portions than the annular iron core pieces. Thus, the divided iron core pieces are connected together more firmly.
FIG. 8A is a plan view of a divided type of laminated iron core 70 used as the stator of a conventional inner-rotor type motor, FIG. 8B is a plan view of a divided laminated iron core 71 for use in the laminated iron core 70 shown in FIG. 8A, and FIG. 8C is a sectional view taken along the VIIIC-VIIIC line shown in FIG. 8B. Also, FIG. 8D is a plan view of a non-divided type of laminated iron core 75 used as the stator of a conventional outer-rotor type motor.
As shown in FIG. 8A and FIG. 8B, the laminated iron core 70 used as the stator of the inner-rotor type motor is structured by combining together multiple divided laminated iron cores 71, while the divided laminated iron core 71 is structured by laminating multiple divided iron core pieces 60. The divided iron core piece 60 includes a magnetic pole shaft piece 61 and a divided yoke portion 62. The divided yoke portion 62 forms a portion of the annular yoke portion 72 of the laminated iron core 70, while the magnetic pole shaft piece 61 forms a magnetic pole shaft portion 73 projecting from the yoke portion 72 toward the inner periphery of the laminated iron core 70.
In this divided iron core piece 60, the magnetic pole shaft piece 61 includes a caulking section 63, while the divided yoke portion 62 includes three caulking sections 64, 65 and 66. These caulking sections 63, 64, 65 and 66 are the same in size and shape.
The caulking sections 63, 64, 65 and 66, as shown in FIG. 8C, are formed to project toward one side in the laminating direction; and, each caulking section includes a projecting sub-section 68 on one side in the laminating direction and a recessed sub-section 67 on the other side in the laminating direction. The projecting sub-sections 68 of the caulking sections 63, 64, 65 and 66 are fitted into the recessed sub-sections 67 of the divided iron core pieces 60 situated on one side in the laminating direction, whereby the divided iron core pieces 60 mutually adjoining in the laminating direction are connected to each other.
Also, as shown in FIG. 8D, similarly in the non-divided type of laminated iron core 75 used as the stator of the outer-rotor type motor, the magnetic pole shaft pieces 76 and yoke pieces thereof respectively include caulking sections 77, 79 which are the same in size and shape.